Preliminary Outcome of Microwave Ablation of Hepatocellular Carcinoma: Breaking the 3-cm Barrier?

Refining MR-guided thermal ablation for HCC within the Milan criteria: a decade of clinical outcomes and predictive modeling at a single institution

BACKGROUND

The appropriateness of ablation for liver cancer patients meeting the Milan criteria remains controversial.

PURPOSE

This study aims to evaluate the long-term outcomes of MR-guided thermal ablation for HCC patients meeting the Milan criteria and develop a nomogram for predicting survival rates.

METHODS

A retrospective analysis was conducted from January 2009 to December 2021 at a single institution. Patients underwent MR-guided thermal ablation. Factors influencing progression-free survival (PFS) and overall survival (OS) were identified using univariate and multivariate Cox regression and stepwise regression. A nomogram was developed for survival prediction, followed by risk stratification and internal validation. Adverse events (AEs) were also analyzed.

RESULTS

A total of 181 patients were included, with a mean follow-up of 73.8 ± 31.7 months. The cumulative local tumor progression rates at 1, 3, and 5 years were 0.80%, 1.27%, and 1.86%, respectively. The 1-, 3-, and 5-year PFS rates were 81.8%, 57.4%, and 38.1%, and OS rates were 98.3%, 87.8%, and 62.9%. Poorer outcomes were associated with age ≤ 60 years, tumor size > 2 cm, multiple tumors, cirrhosis, proximity to major vessels, and narrow ablation margins (P < 0.05). The nomogram accurately predicted 3- and 5-year survival, and internal validation confirmed the results. AEs occurred in 33.7% of patients, with pain being the most common.

CONCLUSION

MR-guided ablation is effective for HCC patients within the Milan criteria, especially for those with smaller tumors and better liver function. The nomogram and risk stratification model are valuable tools for predicting patient outcomes and guiding treatment.

Past, present, and future perspectives of ultrasound-guided ablation of liver tumors: Where could artificial intelligence lead interventional oncology?

The first ablation procedures for small hepatocellular carcinomas were percutaneous ethanol injection under ultrasound (US) guidance. Later, radiofrequency ablation was shown to achieve larger coagulation areas than percutaneous ethanol injection and became the most used ablation technique worldwide. In the past decade, microwave ablation systems have achieved larger ablation areas than radiofrequency ablation, suggesting that the 3-cm barrier could be broken in the treatment of liver tumors. Likewise, US techniques to guide percutaneous ablation have seen important progress. Contrast-enhanced US (CEUS) can define and target the tumor better than US and can assess the size of the ablation area after the procedure, which allows immediate retreatment of the residual tumor foci. Furthermore, fusion imaging fuses real-time US images with computed tomography or magnetic resonance imaging with significant improvements in detecting and targeting lesions with low conspicuity on CEUS. Recently, software powered by artificial intelligence has been developed to allow three-dimensional segmentation and reconstruction of the anatomical structures, aiding in procedure planning, assessing ablation completeness, and targeting the residual viable foci with greater precision than CEUS. Hopefully, this could lead to the ablation of tumors up to 5-7 cm in size.

Numerical modeling and validation of combination embolization-ablation therapy in the liver using dynamic contrast-enhanced (DCE)-MRI

Combination transarterial embolization and ablation is an increasingly common strategy for treating solitary, non-resectable hepatocellular carcinomas (HCCs) greater than 3 cm in size. However, manufacturer guidelines do not provide information as to the size of the ablation zone after embolization. This can put the patient at risk for inadvertent thermal damage to nearby anatomy such as the liver capsule, biliary ducts, diaphragm, and body wall. Thus, while combination therapy is associated with improved clinical outcomes, it is also associated with a higher complication rate. The goal of this study was to create a numerical model to evaluate the change in perfusion in embolization and correlate the perfusional change with final microwave ablation volume. This relationship was then validated in combination embolization ablation therapy in an in-vivo porcine liver model, using a novel MR perfusion sequence.

Treatment options for solitary hepatocellular carcinoma ≤5 cm: surgery vs. ablation: a multicenter retrospective study

BACKGROUND/AIM

The aim of this study was to compare the therapeutic efficacy of ablation and surgery in solitary hepatocellular carcinoma (HCC) measuring ≤5 cm with a large HCC cohort database.

METHODS

The study included consecutive 2,067 patients with solitary HCC who were treated with either ablation (n=1,248) or surgery (n=819). Th e patients were divided into three groups based on the tumor size and compared the outcomes of the two therapies using propensity score matching.

RESULTS

No significant difference in recurrence-free survival (RFS) or overall survival (OS) was found between surgery and ablation groups for tumors measuring ≤2 cm or >2 cm but ≤3 cm. For tumors measuring >3 cm but ≤5 cm, RFS was significantly better with surgery than with ablation (3.6 and 2.0 years, respectively, P=0.0297). However, no significant difference in OS was found between surgery and ablation in this group (6.7 and 6.0 years, respectively, P=0.668).

CONCLUSION

The study suggests that surgery and ablation can be equally used as a treatment for solitary HCC no more than 3 cm in diameter. For HCCs measuring 3-5 cm, the OS was not different between therapies; thus, ablation and less invasive therapy can be considered a treatment option; however, special caution should be taken to prevent recurrence.

Combination transarterial chemoembolization and microwave ablation vs. microwave ablation monotherapy for hepatocellular carcinomas greater than 3 cm: a comparative study

PURPOSE

To evaluate the efficacy of combination therapy using transarterial chemoembolization with microwave ablation (MWA) therapy vs. MWA monotherapy for hepatocellular carcinomas (HCCs) >3 cm in size.

METHODS

This two-arm retrospective observational study included patients with HCCs >3 cm who underwent either combination therapy (29 patients) or MWA monotherapy (35 patients) between 2014 and 2020. The treatment outcomes related to primary treatment efficacy, local tumor progression (LTP), tumor control rate, and overall survival were compared between each cohort.

RESULTS

The technical success and primary efficacy were 96.56% and 100.00% in the combination therapy cohort, and 91.42% and 100.00% in the MWA cohort, respectively, over a mean follow-up period of 27.6 months. The 1- and 3-year rates of LTP-free survival were 78.57% and 69.56% in the combination therapy cohort, vs. 72.45% and 35.44% in the MWA cohort, respectively (P = 0.001). The overall progression-free survival was longer in the combination therapy cohort compared with the MWA cohort (median: 56.0 vs. 13.0 months; P = 0.017). With the incorporation of additional locoregional therapy, the overall survival rates were not significantly different, with 1- and 3-year overall survival rates of 100.00% and 88.71% in the combination therapy cohort and rates of 90.15% and 82.76% in the MWA cohort, respectively (P = 0.235).

CONCLUSION

The combination therapy provided significantly longer upfront LTP-free survival in HCCs >3 cm when compared with the MWA treatment alone, albeit with similar local tumor control and overall survival rates when accounting for additional locoregional therapies.

Comparable and Complimentary Modalities for Treatment of Small-Sized HCC: Surgical Resection, Radiofrequency Ablation, and Microwave Ablation

BACKGROUND

Over the past decade, there has been continual improvement in both ablative and surgical technologies for the treatment of hepatocellular carcinoma (HCC). The efficacy of ablative therapy compared to surgical resection for HCC has not been thoroughly evaluated using multiple large-scale randomized controlled trials. By international consensus, if a patient is eligible, surgery is the primary curative treatment option, as it is believed to confer superior oncologic control.

OBJECTIVE

to determine the efficacies of percutaneous ablative therapies and surgical resection (SR) in the treatment of HCC. Data sources, study appraisal, and synthesis methods: A meta-analysis using 5 online databases dating back to 1989 with more than 31,000 patients analyzing patient and tumor characteristics, median follow-up, overall survival, and complication rate was performed.

RESULTS

Ablative therapies are suitable alternatives to surgical resection in terms of survival and complication rates for comparable patient populations. For the entire length of the study from 1989-2019, radiofrequency ablation (RFA) produced the highest 5-year survival rates (59.6%), followed by microwave ablation (MWA) (50.7%) and surgical resection (SR) (49.9%). In the most recent era from 2006 to 2019, surgical resection has produced the highest 5-year survival rate of 72.8%, followed by RFA at 61.7% and MWA at 50.6%. Conclusions and key findings: Depending on the disease state and comorbidities of the patient, one modality may offer superior overall survival rates over the other available techniques. Interventional ablative methods and surgical resection should be used in conjunction for the successful treatment of small-sized HCC.

Microwave ablation for hepatic malignancies: a systematic review of the technology and differences in devices

BACKGROUND

Microwave ablation (MWA) has become the standard thermal-based treatment for hepatic malignancies in patients who have unresectable disease based on the biology of the tumor, the patients' comorbidities, and certain disease sites. The technical effectiveness, ablation success, local recurrence rates of hepatic malignancies treated with the various commercial microwave ablation devices has not been previously published in the peer reviewed literature. The aim of this systematic review is to summarize the clinical outcomes for the various MWA devices in the use of a hepatic malignancies to best educate hepatic surgeons as well as interventional radiologists.

METHODS

A comprehensive review of the literature and instructions for use of each device that was published from 1/2013 to 12/2020 was performed. The main outcomes extracted were technical success, ablation success, major complications, local and new recurrence rates, recurrence-free survival, ablation volumes, time, and the number of antennas required. A qualitative review of the literature was performed.

RESULTS

In total, 29 studies reporting data on 3250 patients and 4500 tumors were included in this review. Median patient age was 60.5 years (range 3-91). 76.3% (2420 M/753 F) of patients were male. Hepatocellular carcinoma (55%) was the most common tumor pathology followed by colorectal liver metastasis (10%) and cholangiocarcinoma (4%). A majority of studies reported technical success (range, 91.6-100%) and ablation success (range, 73.1-100%), as well as major complications (range, 0-9.1%). Local recurrence (range, 0-50%) was reported by 21 of the studies; however, new recurrence (range, 12.2-64%) was reported less frequently (6 studies) and were further specified in 12, six, and four studies as intrahepatic distant recurrence (11.3-54.2%), extrahepatic distant recurrence (3.6-20%), and metastasis (1.1-36%). A total of three, six, and five studies report disease, progression, and recurrence-free survival rates, respectively.

CONCLUSION

Microwave ablation is frequently used for the treatment of hepatic malignancies. A thorough understanding of the clinical outcomes associated with different pathologies and MWA devices can improve surgeon awareness and help prepare for operative planning and patient management. More consistent reporting of key outcomes in the literature is needed to achieve such an understanding.

Single medium-sized hepatocellular carcinoma treated with sequential conventional transarterial chemoembolization (cTACE) and microwave ablation at 4 weeks versus cTACE alone: a propensity score

Background

Microwave ablation (MWA) is a potentially curative treatment for unresectable patients with hepatocellular carcinoma (HCC) ≤ 3 cm, while its therapeutic efficacy decreases significantly for HCC > 3cm. Previous studies have demonstrated that conventional transarterial chemoembolization (cTACE) combined with MWA (cTACE-MWA) may improve local tumor control rate and reduce the recurrence rate for HCC > 3cm. However, there have been few study designs to analyze the clinical efficacy of cTACE-MWA for medium-sized HCC (3–5cm). Therefore, this study aims to compare the clinical efficacy and safety of cTACE-MWA with cTACE alone for a single medium-sized HCC of 3–5 cm in diameter.

Methods

We retrospectively investigate the data of 90 patients with a single medium-sized HCC who were referred to our hospital and underwent cTACE-MWA or cTACE alone from December 2017 to March 2020. Then, patients were identified with propensity score-matched (1:1). The local tumor response to treatment and time to progression (TTP) were compared using mRECIST criteria between the cTACE-MWA group and the cTACE group.

Results

A total of 42 patients were included after matching (cTACE-MWA: 21; cTACE: 21). Comparing with cTACE, cTACE-MWA demonstrate significantly better local tumor control (ORR: 95.2% vs 61.9%, p = 0.02; DCR: 95.2% vs 66.7%, p = 0.045) and TTP (median 19.8 months vs 6.8 months, p < 0.001). The 1- and 2-year cumulative probabilities of OS were 100% and 95% in the cTACE-MWA group, which were significantly higher than those in the cTACE group (95% and 76%) (p = 0.032). Multivariate Cox regression analysis illustrates that cTACE-MWA was associated with better TTP (hazard ratio, 0.28; 95% CI: 0.1, 0.76; p = 0.012), but tumor size was associated with worse TTP (hazard ratio, 1.71; 95% CI: 1.01, 2.89; p = 0.045).

Conclusions

cTACE followed by MWA improved TTP and OS in patients with a single medium-sized HCC, and no major complication was observed in this study.

Efficacy and Safety of Fusion Imaging in Radiofrequency Ablation of Hepatocellular Carcinoma Compared to Ultrasound: A Meta-Analysis

Background: Radiofrequency ablation (RFA), generally performed under real-time guidance of ultrasound which is safe and effective, is a common minimally invasive therapy for treating hepatocellular carcinoma. Fusion imaging (FI) is a newly developed imaging method, which integrates CT/MRI accurate imaging and matches the characteristics of real-time ultrasound imaging, thereby providing a new approach to guide tumor ablation therapy. However, the efficacy and safety of FI as opposed to ultrasound in tumor ablation remains unclear.

Objective: The present study sought to evaluate the difference in the efficacy and safety between FI and ultrasound in radiofrequency surgery for the treatment of hepatocellular carcinoma through a metaanalysis.

Materials and Methods: Searching for studies comparing the efficacy and safety of FI and ultrasound in radiofrequency of hepatocellular carcinoma in PubMed, Embase, and Cochrane Library databases for articles published until April 2021. Random or fixed effect models were used for statistical analysis. Metaanalysis and sensitivity analysis were used on the included studies.

Results: A total of six studies met predefined inclusion criteria, and were finally included in the analysis. Sensitivity and subgroup analyses, based on predetermined patient characteristics, allowed minimization of bias. In the RFA of hepatocellular carcinoma, FI decreased 1-year overall survival (OS) when compared with ultrasound. But FI was not significantly different from ultrasound in terms of technical efficiency, 1-, 2-, and 3-year local tumor progression (LTP), complications, as well as 2-year OS. Subgroup analysis, based on tumor mean diameter, showed that FI reduced the rate of 1- and 2-year LTP in patients with tumors of mean diameter ≥15 mm when compared with ultrasound. Moreover, operative complications could be reduced in patients with tumor mean diameter <15 mm using FI, compared with ultrasound.

Conclusion: Overall, these results showed that FI may have some effects on improving efficacy and safety of thermal ablation in HCC patients, relative to ultrasound. However, it may be a more effective method for managing large lesions, as well as those that are difficult to ablate. Further large-scale and well-designed randomized controlled trials are needed to validate these findings.

Image-guided locoregional non-intravascular interventional treatments for hepatocellular carcinoma: Current status

Hepatocellular carcinoma (HCC) is one of the most deadly and frequent cancers worldwide, although great advancement in the treatment of this malignancy have been made within the past few decades. It continues to be a major health issue due to an increasing incidence and a poor prognosis. The majority of patients have their HCC diagnosed at an intermediate or advanced stage in theUSA or China. Curative therapy such as surgical resection or liver transplantation is not considered anoption of treatment at these stages.

Transarterial chemoembolization (TACE), the most widely used locoregional therapeutic approach, used to be the mainstay of treatment for cases with unresectable cancer entities. However, for those patients with hypovascular tumors or impaired liver function reserve, TACE is a suboptimal treatment option. For example, embolization does not result in complete coverage of a hypovascular tumor, and may rather promotes postoperative tumor recurrence, or leave residual tumor, in these TACE-resistance patients. In addition, TACE carries a higher risk of hepatic decompensation in patients with poor liver function or reserve.

Non-vascular interventional locoregional therapies for HCC include radiofrequency ablation (RFA), microwave ablation (MWA), high-intensity focused ultrasound (HIFU), laser-induced thermotherapy (LITT), cryosurgical ablation (CSA), irreversible Electroporation (IRE), percutaneous ethanol injection (PEI), and brachytherapy. Recent advancements in these techniques have significantly improved the treatment efficacy of HCC and expanded the population of patients who qualify for treatment. This review embraces the current status of imaging-guided locoregional non-intravascular interventional treatments for HCCs, with a primary focus on the clinical evaluation and assessment of the efficacy of combined therapies using these interventional techniques.

The Short-Term Efficacy of Novel No-Touch Combined Directional Perfusion Radiofrequency Ablation in the Treatment of Small Hepatocellular Carcinoma with Cirrhosis

BACKGROUND

No-touch combined directed perfusion radiofrequency ablation (NTDP-RFA) is a new technique for the treatment of hepatocellular carcinoma (HCC). The purpose of this study was to evaluate the short-term efficacy of this new technique for the treatment of small HCC with cirrhosis.

METHODS

From January 2017 to March 2018, 56 consecutive patients treated with NTDP-RFA at our center were enrolled in this retrospective study. All NTDP-RFA procedures involved the use of internally cooled wet electrodes with a directional injection function, which can perform both intraelectrode cooling and extraelectrode saline perfusion. Survival curves were analyzed using Kaplan-Meier methods, and Cox proportional hazards regression analyses were used to assess predictors of tumor progression and overall survival. Operative characteristics and complications were also assessed.

RESULTS

No technical failure occurred, and the complete ablation rate after single NTDP-RFA treatment was 98.2%. The median tumor diameter and ablation time were 26 (18.0 - 28.0) mm and 8 (6 - 8) min, respectively. Mild complications occurred in five patients (8.9%) postoperatively, and the median hospital stay was 4 (4 - 5) days. In the 18 patients (32.1%) with poor liver function reserve (indocyanine green retention rate at 15 min > 15%, their liver function returned to normal on the third day after the postoperation. The 1- and 2-year local and distant progression rates were 1.7%, 7.1%, 3.5% and 10.7%, respectively.

CONCLUSIONS

NTDP-RFA in the treatment of small HCC with cirrhosis has a low incidence of complications and provides a high survival rate without local tumor progression.

Transarterial Yttrium-90 Radioembolization of Hepatocellular Carcinoma Perfused by the Cystic Artery: Multi-institutional Feasibility Study

PURPOSE

To assess the safety and efficacy of transarterial yttrium-90 radioembolization via the cystic artery for patients with hepatocellular carcinoma (HCC) adjacent to the gallbladder with cystic artery supply.

MATERIALS AND METHODS

This retrospective study included 17 patients treated at 4 institutions. Patients with HCC perfused by the cystic artery who received ablative-dose radioembolization were included. Median tumor size was 3.8 cm (range, 2.0-8.8 cm). Fourteen patients (82%) had Child-Pugh class A cirrhosis and 3 (18%) had class B cirrhosis. Adverse events, tumor response, and time to progression were analyzed.

RESULTS

Median dose to the tissue perfused by the cystic artery was 340 Gy (range, 200-720 Gy). There were no occurrences of acute cholecystitis warranting invasive intervention. Four patients (24%) experienced transient right upper quadrant pain, with symptom resolution within 3 mo. Six patients (35%) exhibited gallbladder wall edema on follow-up imaging. Two (12%) and 0 grade 3/4 increases in alkaline phosphatase and bilirubin were observed, respectively. Follow-up imaging demonstrated complete response in 13 target tumors (76%) and partial response in 4 (24%). There were no cases of target tumor progression during a median follow-up of 9 mo (range, 3-72 mo).

CONCLUSIONS

Direct infusion of 90Y microspheres via the cystic artery appears to have an acceptable safety profile, without resulting in acute cholecystitis warranting invasive intervention. In selected patients with HCC in whom other treatments may be contraindicated and the tumor is supplied via the cystic artery, treatment with selective ablative radioembolization can be considered.

The effect of tumor location on long-term results of microwave ablation for early-stage hepatocellular carcinoma

BACKGROUND

To analyze the influence of tumor location, including tumor adjacency and located segments on long-term survival outcomes for patients with solitary hepatocellular carcinoma (HCC) after microwave ablation (MWA).

METHODS

This retrospective study evaluated 850 patients. The hepatic segments where the tumor is located, tumor adjacency (important tissues adjacent to tumor) and other clinical characteristics were collected. Overall survival (OS), local tumor progression (LTP) and disease-free survival (DFS) were compared and analyzed. Influence of tumor location was evaluated by multi-models and the effect of adjacency for OS, LTP, and DFS in different segments was analyzed by stratification analysis.

RESULTS

The OS, LTP, and DFS rates were similar in different hepatic segments, so were in high risk and safe locations. In multi-models, HCC in segment 8 showed lower death rate of 43% than that in segment 2 (HR 0.57; P = 0.01) and tumors in segment 6 seemed to have lower LTP rate. Tumors in high-risk locations were risk factors for OS, LTP, and DFS compared with tumors in safe locations, but all differences were not significant in different models. The effects of tumor adjacency on survival outcomes among subgroups of segments were limited.

CONCLUSION

The tumor adjacency was not a prognostic factor of survival outcomes for patients with solitary tumors after MWA, but tumors in segment 8 seemed to better OS rate than tumors in other segments.

Radiofrequency ablation with four electrodes as a building block for matrix radiofrequency ablation: Ex vivo liver experiments and finite element method modelling. Influence of electric and activation mode on coagulation size and geometry

PURPOSE

Radiofrequency ablation (RFA) is increasingly being used to treat unresectable liver tumors. Complete ablation of the tumor and a safety margin is necessary to prevent local recurrence. With current electrodes, size and shape of the ablation zone are highly variable leading to unsatisfactory local recurrence rates, especially for tumors >3 cm. In order to improve predictability, we recently developed a system with four simple electrodes with complete ablation in between the electrodes. This rather small but reliable ablation zone is considered as a building block for matrix radiofrequency ablation (MRFA). In the current study we explored the influence of the electric mode (monopolar or bipolar) and the activation mode (consecutive, simultaneous or switching) on the size and geometry of the ablation zone.

MATERIALS AND METHODS

The four electrode system was applied in ex vivo bovine liver. The electric and the activation mode were changed one by one, using constant power of 50 W in all experiments. Size and geometry of the ablation zone were measured. Finite element method (FEM) modelling of the experiment was performed.

RESULTS

In ex vivo liver, a complete and predictable coagulation zone of a 3 × 2 × 2 cm block was obtained most efficiently in the bipolar simultaneous mode due to the combination of the higher heating efficacy of the bipolar mode and the lower impedance by the simultaneous activation of four electrodes, as supported by the FEM simulation.

CONCLUSIONS

In ex vivo liver, the four electrode system used in a bipolar simultaneous mode offers the best perspectives as building block for MRFA. These results should be confirmed by in vivo experiments.

Fusion imaging techniques and contrast-enhanced ultrasound for thermal ablation of hepatocellular carcinoma - A prospective randomized controlled trial

Objectives: This randomized controlled trial (RCT) aims to compare the clinical application values of contrast-enhanced ultrasound (CEUS), computed tomography/magnetic resonance-CEUS (CT/MR-CEUS), and three-dimensional ultrasound-CEUS (3DUS-CEUS) Fusion imaging (FI) techniques in the assistance of thermal ablation for hepatocellular carcinoma (HCC).Methods: A RCT was conducted on 374 patients with 456 HCCs between January 2016 and September 2017. CEUS, CT/MR-CEUS, and 3DUS-CEUS FI techniques were randomly used to assist HCC ablation. All lesions were ablated according to a previously determined plan, and FI groups required a 5-mm ablative margin. The primary endpoints were technical efficacy of thermal ablation and local tumor progression (LTP).Results: According to randomization, 153 (18.8 ± 8.0 cm), 153 (18.3 ± 6.6 cm) and 150 (19.1 ± 6.9 cm) HCCs were assigned to CT/MR-CEUS, 3DUS-CEUS and CEUS groups respectively. Technical efficacy rates (99.3% vs. 100% vs. 100%) were achieved in the three groups, showing no statistical differences (p = 1.000). The median follow-up time was 24 (1-37) months. LTP rates at 1 and 2 years were 3.4%, 12.2% for CT/MR-CEUS FI, 4.8%, 9.0% for 3DUS-CEUS FI, and 8.6%, 19.9% for CEUS, respectively (p = .105). The results of subgroup analysis for LTP were statistically significant when patients with albumin-bilirubin (ALBI) grade 2 and 3 (p = .000), and tumor located at risky positions (p = .042). In addition, the p value in group of multiple tumors was close to .05 (p = .052).Conclusions: All the three techniques are feasible for intraoperative HCC thermal ablation. Compared with CEUS, FI techniques are more suitable in patients with ALBI grade 2 and 3, multiple tumors, and in tumors at risky locations.

Locoregional Therapies in the Treatment of 3- to 5-cm Hepatocellular Carcinoma: Critical Review of the Literature

OBJECTIVE. Treatment options for hepatocellular carcinoma (HCC) continue to expand. However, given the complexity of the patients including factors such as codominant cirrhosis or portal hypertension and transplant status, it can be difficult to know which treatment is most advantageous. The choice of HCC treatment is perhaps most complex in the setting of HCCs that are 3-5 cm. This article reviews the evidence for locoregional therapies in treating 3- to 5-cm HCCs. CONCLUSION. Combination therapy with transarterial chemoembolization (TACE) and ablation has the most robust and highest level of evidence to support its efficacy and therefore should be considered first-line therapy for nonresectable HCCs that measure 3-5 cm. The studies support that TACE followed by ablation is superior to either TACE alone or ablation alone. Data for transarterial radioembolization (TARE) to treat HCCs in this specific size range are very limited. Additional data are needed about the comparative effectiveness of TACE-ablation combination and TARE and how the TACE-ablation combination compares with surgical resection.

Early Outcomes with Single-antenna High-powered Percutaneous Microwave Ablation for Primary and Secondary Hepatic Malignancies: Safety, Effectiveness, and Predictors of Ablative Failure

Objective:

Microwave ablation (MWA) of liver malignancies has gained much traction over the past 5 years. However, MWA carries relatively higher rates of residual disease compared to resection. Likelihood of MWA success is multifactorial and newer devices with more reliable ablation zones are being developed to overcome these drawbacks. This manuscript is a review of our first 100 liver ablations with the newer single antenna high powered MWA system.

Materials and Methods:

Retrospective chart review of patients that underwent MWA for either primary or secondary hepatic malignancies between March 2015 and July 2016 was conducted. The complete ablation rates, rate of new lesions, complications, and short-term survival were analyzed. Multiple statistical tests, including multivariate regression, were used to assess risk factors for local residual and recurrent disease.

Results:

Fifty-three patients (median age 61 ± 9 years, 39 males) underwent 100 MWAs. Of the 100 lesions ablated, 76 were hepatocellular cancers (HCCs) and 24 were metastases. Median lesion size was 16 ± 9 mm. Seventy- five of these patients had multifocal disease targeted in the same session. Seventy patients had cirrhosis (median model for end-stage liver disease score 9 ± 3; Child-Pugh B and C in 42%). An 83% complete lesion ablation rate was seen on follow-up imaging with liver protocol magnetic resonance imaging/computed tomography (median follow-up of 1 year). The minor complication rate was 9.4% with no major complications or 30-day mortality. Despite this, evidence of new foci of hepatic disease was found in 47% of patients, the majority (80%) of which were in HCC patients (P < 0.01) and most of these new lesions were in a different hepatic segment (64%). Degree of cirrhosis (P < 0.01), presence of non-alcoholic steatohepatitis (NASH) (P = 0.01) and lesion’s subcapsular location (P = 0.03) was significant predictors of residual disease. With the subset analysis of only HCC lesions larger than 1 cm, only the presence of NASH remained significant.

Conclusion:

The single probe high power MWA of malignant hepatic lesions is safe and effective with minimal morbidity. Degree of cirrhosis, NASH, and subcapsular location was associated with an increased rate of residual disease on short-term follow-up.

Indications of external radiotherapy for hepatocellular carcinoma from updated clinical guidelines: Diverse global viewpoints

The etiology and disease patterns of hepatocellular carcinoma (HCC) significantly vary among regions. Modern standard treatments commonly require multidisciplinary approaches, including applications of up-to date medicine and advanced procedures, and necessitate the support of socioeconomic systems. For these reasons, a number of clinical guidelines for HCC from different associations and regions have been presented. External beam radiation therapy was contraindicated for HCC until a few decades ago, but with the development of new technologies, its application has rapidly increased as selective irradiation for tumorous lesions became possible. Most of the guidelines had been opposed or indifferent to radiotherapy in the past, but several guidelines have introduced indications and recommendations for radiotherapy in their updated versions. This review will discuss the characteristics of important guidelines and their contents regarding radiotherapy and will also provide guidance to physicians who are considering applications of locoregional modalities that include radiotherapy.

Percutaneous microwave ablation for HCV-related hepatocellular carcinoma: Efficacy, safety, and survival

BACKGROUND/AIMS

Hepatocellular carcinoma (HCC) has a poor prognosis if managed late. Percutaneous microwave ablation (MWA) emerged as one of the top therapeutic decisions for non-surgical patients. The aim of the present study aim was to evaluate the efficacy, side effects, and survival after MWA of hepatitis C virus (HCV)-related HCC tumors with spectrum sizes up to 5 cm.

MATERIALS AND METHODS

Fifty-nine patients with early HCC were treated in the Hepatology Department using percutaneous MWA. Patients were assessed for side effects and efficacy that includes the rate of complete ablation, primary or de novo recurrence, and survival.

RESULTS

Complete ablation was achieved in 57 (96.6%) patients treated by MWA, with a minor complication rate of 3.3% (n=2) including liver abscess formation and abdominal skin burn. The ablation rates in lesions <3 versus 3-5 cm were not different. Of the patients, 3 (5%) had primary recurrence in the treated HCC tumors, de novo lesions (secondary recurrence) developed in 8 (13.5%, 5 of them >3 cm), and 2 (3.3%) had malignant portal vein thrombosis. The survival rates were 95.4% and 69% at 1 and 2 years, respectively.

CONCLUSION

Percutaneous MWA had achieved a safe and effective treatment with good overall survival in patients with HCV-related HCC.

The Combination Strategy of Transarterial Chemoembolization and Radiofrequency Ablation or Microwave Ablation against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver. Hepatectomy and liver transplantation (LT) are regarded as the radical treatment, but great majority of patients are already in advanced stage on the first diagnosis and lose the surgery opportunity. Multifarious image-guided interventional therapies, termed as locoregional ablations, are recommended by various HCC guidelines for the clinical practice. Transarterial chemoembolization (TACE) is firstly recommended for intermediate-stage (Barcelona Clinic Liver Cancer (BCLC) B class) HCC but has lower necrosis rates. Radiofrequency ablation (RFA) is effective in treating HCCs smaller than 3 cm in size. Microwave ablation (MWA) can ablate larger tumor within a shorter time. Combination of TACE with RFA or MWA is effective and promising in treating larger HCC lesions but needs more clinical data to confirm its long-term outcome. The combination of TACE and RFA or MWA against hepatocellular carcinoma needs more clinical data for a better strategy. The characters and advantages of TACE, RFA, MWA, and TACE combined with RFA or MWA are reviewed to provide physician a better background on decision.

Comparison of parallel and crossed placement of antennas in microwave ablation of 3-5 cm hepatocellular carcinoma

PURPOSE

To evaluate the effects of ablation strategies on local tumor progression (LTP) after microwave ablation (MWA) of hepatocellular carcinomas (HCCs) measuring 3-5 cm.

MATERIALS AND METHODS

Between December 2011 and May 2017, 71 HCC patients with 71 nodules treated by ultrasound(US)-guided percutaneous MWA were divided into parallel (group A) and crossed (group B) antenna placement groups. All patients underwent MWA using two antennas with four insertions. LTP and overall survival (OS) rates were compared between the two groups.

RESULTS

The median follow-up time was 16.8 months. There was no significant difference in the complete ablation rate and treatment sessions between the two groups. LTP was diagnosed in 8 of 48 nodules (16.7%) in group A and 1 of 23 nodules (4.3%) in group B, with no significant difference between two groups (P = 0.115). The 1-, 2-, and 3-year OS rates were 88.5%, 79%, and 71.8% in group A and 93.8%, 87.5%, and 87.5% in group B, respectively (P = 0.236). Multivariate analysis showed that the tumor diameter (P = 0.017), the distance between the antennas (P = 0.032), and the total emission time (P = 0.015) were associated with LTP.

CONCLUSIONS

There were trends with lower LTP and improved OS in group B, despite the lack of statistically significant differences between the two strategies at a level of P < 0.05. The increase of distance between antennas and total emission time will facilitate reductions in LTP rate.

Safety and efficacy of microwave ablation for breast cancer thoracic metastases

Background

The objective of the study was to assess the safety and efficacy of microwave ablation (MWA) for breast cancer thoracic metastasis.

Materials and methods

Twelve patients in our institution with a single lesion of breast cancer thoracic metastases received MWA and invasive spine surgery from August 2014 to November 2016. MWA was executed using the MWA system (2,450 MHz) at 40 W or 50 W with thermometers to control the ablation end points. The pathology of thoracic metastases was confirmed through intraoperative biopsy before ablation. The postoperative complications were recorded. The patients were followed up at 1, 3 and 6 months with contrast-enhanced computed tomography and magnetic resonance imaging to monitor for tumor recurrence.

Results

The average duration of follow-up for breast cancer thoracic metastases patients (mean age 52.7±8.4 years) was 10.2 months. The rate of postoperative main complications was 8.3% (1/12). The recurrence rate was 16.6% (2/12) as confirmed by persistent enhancement.

Conclusion

MWA may be used as the adjuvant treatment for thoracic metastases of breast cancer. Results showed that few significant complications and less local recurrence occurred during the follow-up stage. Future research should aim at discovering more about the time controls for microwave-tissue interaction and treatment parameters before widespread use.

Microwave ablation combined with transcatheter arterial chemoembolization is effective for treating unresectable hepatoblastoma in infants and children

The present study is to evaluate the feasibility and efficacy of microwave ablation (MWA) combined with transcatheter arterial chemoembolization (TACE) in the treatment for unresectable hepatoblastoma in infants and children. A total of 17 patients with PRETEXT stage III and IV hepatoblastoma that was unresectable by conventional resection were included in the present study. The patients were treated with TACE, MWA, and chemotherapy. All cases were diagnosed by computed tomography (CT) and liver tumor biopsy before TACE procedure. All patients received 2 courses of TACE and 1 to 2 times of MWA. Finally, several cycles of chemotherapy were arranged. Among the 17 patients, 14 were alive and had normal alpha-fetoprotein (AFP) levels. The other 3 patients died from tumor progression. The follow-up periods ranged from 10 to 68 months. Complete ablation was achieved in the 14 patients (14/17, 82.35%). Most patients were well tolerated during the whole course except for 1 patient with pneumonedema after TACE and another 1 with biloma after MWA. No marked chemotherapeutic agent-induced toxicity occurred. After chemotherapy or TACE, transient blood indicators and symptoms were observed as follows: myelosuppression, abnormal liver function, gross hematuria, fever, and abdominal pain. Transient symptoms after MWA were fever, abdominal pain, and massive gross hematuria. The present study demonstrates that MWA combined with TACE is a safe and effective method for treating unresectable hepatoblastoma in infants and children with controllable side effects.

A Radiologist's View of Tumor Ablation in the Radiology Suite

Image-guided percutaneous, minimally invasive ablation techniques offer a wide variety of new modalities to treat tumors in some of the most medically complicated patients coming to our hospitals. The use of computed tomography, PET, ultrasound imaging, and MRI to guide radiofrequency ablation, microwave ablation, and cryoablation techniques now makes it possible to treat patients on a short stay or outpatient basis with very good immediate outcomes. This rapid expansion of new tumor ablation techniques often presents challenges for the non-operating room anesthesia team. Collaboration and communication between the radiologist and anesthesiologist are key to safety and excellent patient outcomes.

Delineation of Post-Procedure Ablation Regions with Electrode Displacement Elastography with a Comparison to Acoustic Radiation Force Impulse Imaging

We compared a quasi-static ultrasound elastography technique, referred to as electrode displacement elastography (EDE), with acoustic radiation force impulse imaging (ARFI) for monitoring microwave ablation (MWA) procedures on patients diagnosed with liver neoplasms. Forty-nine patients recruited to this study underwent EDE and ARFI with a Siemens Acuson S2000 system after an MWA procedure. On the basis of visualization results from two observers, the ablated region in ARFI images was recognizable on 20 patients on average in conjunction with B-mode imaging, whereas delineable ablation boundaries could be generated on 4 patients on average. With EDE, the ablated region was delineable on 40 patients on average, with less imaging depth dependence. Study of tissue-mimicking phantoms revealed that the ablation region dimensions measured on EDE and ARFI images were within 8%, whereas the image contrast and contrast-to-noise ratio with EDE was two to three times higher than that obtained with ARFI. This study indicated that EDE provided improved monitoring results for minimally invasive MWA in clinical procedures for liver cancer and metastases.

Advantages of Laparoscopic Radiofrequency Ablation Over Percutaneous Radiofrequency Ablation in Hepatocellular Carcinoma

BACKGROUND

Inoperable hepatocellular carcinoma (HCC) can be treated with laparoscopic radiofrequency ablation (LRFA), which is generally a more accurate and accessible procedure than percutaneous RFA (PRFA). However, few studies have compared survival outcomes between LRFA and PRFA in patients with HCC.

AIMS

This study aimed to compare the efficacy of LRFA and PRFA for HCC treatment.

METHODS

Patients who underwent PRFA or LRFA as an initial treatment modality between April 2005 and April 2016 were enrolled in this study. The overall and recurrence-free survival rates were examined for each patient. Additionally, propensity score matching was performed for both groups.

RESULTS

The baseline characteristics of patients in the PRFA and LRFA groups showed several minor differences. Multivariate analysis showed that the RFA method was not a critical determinant of recurrence-free or overall survival (p = 0.069 and p = 0.406). Among patients who underwent RFA as the initial treatment modality, there was no significant effect between either RFA procedures on survival. After propensity score matching, univariate analysis showed a significant difference in overall survival between PRFA and LRFA (p = 0.031). Multivariate analysis showed that LRFA is a strong factor that contributed to an improved overall survival in HCC patients (hazard ratio 0.108, p = 0.040). Furthermore, our data showed that LRFA was able to limit multiple intrahepatic recurrences, as well as prevent marginal recurrence.

CONCLUSIONS

LRFA appears to be superior to PRFA in terms of survival. LRFA may help reduce mortality in HCC patients.

Loco-regional treatment of HCC: current status

Hepatocellular carcinoma (HCC) represents one of the few cancers for which locoregional treatments are recognised as being able to cure and/or prolong survival and are included in international guidelines. This is due to the unique nature of HCC, in most cases occurring in patients with underlying virus- or alcohol-related cirrhosis. The treatment choice in patients with HCC is therefore driven not only by tumour staging, as in the great majority of cancers, but also by careful evaluation of liver function and physical status. Another specific feature of HCC is that it is the only tumour that can be cured by organ transplantation, with the aim of treating both the cancer and underlying liver disease. These characteristics configure a complex scenario and prompt the need for close cooperation among interventional oncologists, surgeons, hepatologists, and anaesthesiologists. In patients with limited hepatic disease, preserved hepatic function and good performance status, categorised as very early and early-stage HCC according to the Barcelona Clinic Liver Cancer (BCLC) classification, image-guided tumour ablation is included among the curative treatments. More than half of patients with HCC are, however, diagnosed late, despite the widespread implementation of surveillance programmes, when curative treatments cannot be applied. For patients presenting with multinodular HCC and relatively preserved liver function, absence of cancer-related symptoms, and no evidence of vascular invasion or extrahepatic spread transcatheter arterial chemoembolisation (TACE) is the current standard of care. Although anti-tumour activity and promising survival results has been reported in cohorts of patients with advanced HCC treated with radio-embolisation, systemic treatment with the multi-kinase inhibitor, sorafenib, is still recommended for patients at this stage. In this article, current treatment strategies for HCC according to tumour stage are discussed, underlining the latest advances in the literature and technical developments.

Feasibility and Efficacy of Microwave Ablation Combined with Iodine-125 Seed Implantation in Local Control of Recurrent Retroperitoneal Liposarcomas: Initial Clinical Experience

Surgical resection is the primary treatment option for retroperitoneal liposarcomas, but complete resection is difficult and postoperative recurrence and metastasis are common. This prospective study analyzed the feasibility and efficacy of microwave ablation combined with iodine‐125 seed implantation in the local control of recurrent retroperitoneal liposarcomas.

Introduction.

The objective of the present study was to evaluate the feasibility, safety, and short‐term efficacy of microwave ablation (MWA) combined with iodine‐125 (¹²⁵I) seed implantation in recurrent retroperitoneal liposarcomas (rRPLs).

Materials and Methods.

From September 2012 to March 2015, 11 patients were enrolled in this prospective study. Eleven tumors (median, 9 cm; range, 5.5–12.5 cm) were treated with computerized tomography‐guided MWA for 11 sessions and ¹²⁵I seed implantation for 18 sessions. ¹²⁵I seed implantation was performed 4 weeks after MWA.

Results.

There were no procedure‐related deaths. Post‐MWA pain (grade ≥2) was the most common complication (6 of 11 patients, 54.5%), and fever (grade ≥2) was observed in two patients. Reversible nerve injury, defined as transient limb paresthesia or leg weakness, was observed in one patient. There were fewer complications associated with the ¹²⁵I seed implantation procedure compared with the MWA procedure. All 11 patients who underwent the MWA procedure achieved a partial response (PR), according to the modified Response Evaluation Criteria in Solid Tumors, 1 month post‐ablation; after ¹²⁵I seed implantation was performed, a complete response was observed in three, five, and six target tumors in 3, 6, and 12 months, respectively.

Conclusion.

In selected patients with rRPLs, MWA combined with ¹²⁵I seed implantation is feasible and safe with favorable local control efficacy.

Implications for Practice.

This study evaluated the feasibility, safety, and short‐term efficacy of microwave ablation (MWA) combined with iodine‐125 (¹²⁵I) seed implantation in recurrent retroperitoneal liposarcomas (rRPLs). Results suggest that a single session of MWA may be not sufficient in large‐volume rRPLs and that as a supplement treatment, ¹²⁵I seed implantation is safe and easy accessible. MWA combined with ¹²⁵I seed has excellent local control effectiveness, and long‐term efficacy and survival benefit still need to be more comprehensively evaluated.

Comparison of hepatocellular carcinoma in Eastern versus Western populations

Hepatocellular carcinoma (HCC) is a heterogeneous disease that remains highly prevalent in many Asian countries and is the second most common cause of cancer-related mortality worldwide. Significant differences exist between Eastern and Western populations on many key aspects of HCC, contributing to the potential different treatment outcomes and challenges of clinical trial design and data interpretation. In this review, the authors compare HCC in Asia versus the West and highlight 1) differences in terms of epidemiology and trends and their correlation with etiology, 2) differences in genetics and how they relate to underlying etiology, 3) differences in treatment approaches based on existing guidelines and consensus statements, and 4) differences in clinical outcomes for Asian versus non-Asian patients with HCC in clinical trials and the implications for future clinical trial design. Cancer 2016;122:3430-3446. © 2016 American Cancer Society.